A Square Meter for Butterflies

Anthony McCluskey is the Urban Butterfly Project Officer for Butterfly Conservation Scotland, and in this blog, he explains about a project in Edinburgh aiming to increase habitat for butterflies.

Edinburgh was recently found to be the UK city with the greatest proportion of green space – almost half of the city’s area is classified as ‘green’. But there’s always more that can be done, and one of the ways to green the grey jungle is to put wildflowers on top of roofs. Many properties in Edinburgh have green roofs and roof gardens, so I’ve been working with Leonie from Edinburgh Living Landscape to put wildflowers that butterfly caterpillars can eat, onto roofs all over Edinburgh.

Called ‘A Square Meter for Butterflies’, this initiative asks properties to take at least one square meter of each of three plant species: Bird’s-foot Trefoil (Lotus corniculatus ) for Common Blue butterflies; Sheep Sorrel (Rumex acetosella) for Small Copper; and Common Rock-rose (Helianthemum nummularium) for Northern Brown Argus. These have been grown using Scottish native seed, at the Royal Botanic Garden Edinburgh.

The Northern Brown Argus has a great connection with Edinburgh. Naturalists visiting Arthur’s Seat in the late 1700’s first assumed them to be a well-known species called the Brown Argus. But closer examination revealed that they were a completely new species, unknown to science until then.

This caused quite a stir in the butterfly world, and butterfly collectors soon began to trap and kill as many of these butterflies as possible, even paying local children to go up the hill and find them. It’s no surprise that in 1869, less than 100 years after its discovery, the Northern Brown Argus became extinct at Holyrood. But the story doesn’t end there, and somehow the species found its way back to Arthurs seat in 2005, where the colony appears to be doing well. As it needs Common Rock-rose for its caterpillars, we’re placing this wildflower in as many properties around Holyrood as possible (including on top of the Scottish Parliament building itself!) to help welcome this species back to Edinburgh.

Over a dozen other properties will be receiving plants, including the Glenmorangie Whiskey Company, which hosted a small launch reception at their roof garden on Leith Walk. We’re hoping that their example will inspire other businesses to make their buildings havens for wildlife.

Users of these buildings will be offered training in butterfly ID, and asked to keep an eye out for the species we’re interested in. As far as we’re aware, there’s never been a project planting wildflowers specifically for butterfly caterpillars on rooftops. It’s a start, and we’ll be monitoring it to see if it’s something that can be done on a larger scale in cities throughout the UK.